I've got a few others to include, don't know who I'd pick as my #1. For the record, these are completely ignoring any fear I have of possibly not surviving the encounter.

I surprisingly liked Hannah McKay from DexterIf you count Melissandra (Game of Thrones) then her as wellMilady De Winter from The MusketeersSaffron from FireflyArtemesia from 300 Rise of an Empire (yes she is a historical figure, but those movies aren't meant to be faithful adaptations).Miranda Frost (Die Another Day)

OMG lmao This post escalated quickly! XD and yes ANY fictional character. :3 Other people have been giving more than one, so I guess if you have an anime villain bucket list just put the whole thing idc. XD It's just fun to see what everyone likes.

I personally love Izaya Orihara, but he's not really a true villain... *sigh-swoon

OMG I WAS JUST ABOUT TO SAY IZAYA! *links hands in Anime Otaku new friend posture* Eeeeee XD Also Sebastian from Black Butler! Kaneki Ken from Tokyo Ghoul! Soushi from Inu x Boku Secret Service! (the last two as technicalities!) EVERY YANDERE GUY WRITTEN ON QUOTEV, The two guys from Terror in Resonance! uhmmm! what else? I know I have several more ('-')